Device for arming an underwater weapon at shallow depths



Jan. 26, 1965 R. M. SCHMIECH DEVICE ARMING AN UNDERWATER WEAPON AT SHALLOW DEPTHS Filed Jan. 18, 1963 Fl .1. 203% G K YIIIIIIIIH INVENTOR. ROBERT M. SCHMIECH ATTORNEYS.

United States atent 3,1b'lfll3 Patented Jan. 26, 1965 lice 3,167,613 DEVlCE FOR ARMING AN UNFJERWATER WEAPON A'l SHALLDW DEE'fHS Robert M. Schrniech, Silver Spring, Md, assignor to the United States of America as represented by the Secretary of the Navy Filed Jan. 18, 1963, Ser. No. 252,533

10 Claims. (Cl. 1-02-43) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to an underwater weapon for use in shallow water and more particularly to a weapon which is armed in shallow water by immersion therein independently of the hydrostatic pressure applied thereto and in which the pressure of the water at the depth at which the weapon is submerged is increased by a mechanical device within the weapon sufficiently to effect an arming operation thereof.

In devices of this type heretofore proposed it has been the usual practice to discriminate between the impact received by the mine on contact with water and the heavier impact of the mine when landing on a land target after being dropped from an aircraft in flight. Furthermore, an underwater weapon such as a mine heretofore usually employed hydrostatic pressure devices to actuate the various control mechanisms of the mine by the hydrostatic head of the water when the mine is planted therein. Such devices have been subject to the disadvantage that when the mine is planted in very shallow water, for example, there may be insufficient pressure to operate the hydrostatic devices thereof, and furthermore, when launched in shallow water from an aircraft in flight, conditions maybe such that it is impossible for the mine to dis tinguish by the shock received whether the mine is planted on land or in water.

The underwater weapon of the present invention does not rely upon the character of the shock received at the time of planting nor does it rely on the ambient water pressure for its operation and for these reasons is free of the disadvantages which normally attend prior art devices of this character.

In accordance with the present invention the arming of the device is achieved by a motor driven water pump having, the inlet thereof in communication with the ambient water, within which the device is submer ed and the outlet thereof in communication with a piston movable fror an initial safe position to an armed position by the pressure of the water thereagainstwhen the pump has increased the water pressure to a predetermined value. The operation of the device is initiated by the withdrawal of an arming wire which removes a restraint from the piston when in the initial unarmed position thereof and sets the motorinto operation to actuate the pump. In the event that the device does not land in the water after the arming wire has been removed, the pump is ineffective to apply pressure to the piston sufiicient to move it from the initial unarmed position thereof.

One of the objects of the present invention is to provide a shallow water weapon having new and improved means for effecting the arming thereof independently of the depth of the water within which the device is planted.

Another of the objects is to provide means for compensating for the initial pressure of the water when the device is launched from a submerged submarine and to provide new and improved means for delaying the arming thereof until the device is at a safe distance from the submarine.

A still further object is to conserve the source of power within the device by interrupting the operation of the pump motor when the device is in an armed condition.

Still other objects, advantages and improvements will be apparent from the following description taken in connection with the accompanying drawing of which:

FIG. 1 is a view partially in section and partially broken away of a mine employing the present invention in accordance with a preferred embodiment thereof and supported by an airplane;

FIG. 2 is an enlarged view of the mine partially in section and partially broken away on which is shown the arming mechanism in an armed position; and

FIG. 3 is a sectional view partially broken away of the rming device of the present invention in an unarmed condition according to an alternative form thereof.

Referring now to the drawing on which like numerals of reference are employed throughout the several views to designate like parts and more particularly to FIG. 1 thereof there is shown thereon a mine indicated generally by the numeral 10 and having a pair of eye bolts 11 relcasably secured to an airplane 12 by a release mechanism 29 which may comprise a pair of releasable hooks or the like as illustrated. The mine is preferably of the type known as a ground mine which rests upon the bed of the body of water within which it is planted or, if desired, it may be of the type adapted to be moored within the water at a shallow depth of submergence. There is also connected to the ground mine an arming wire 13, the purpose of which will be more clearly apparent as the description proceeds.

There is disposed within the mine an arming piston 14 reciprocal within a cylinder 15 from the initial unarmed position of FIG. 1 to the armed position of FIG. 2. The piston is connected to a shaft 16 extending through the outer casing of the mine substantially as shown and provided with a hole therethrough through which the arming wire 13 normally extends to prevent movement of the piston from the initial unarmed position until the arming wire is removed. A suitable seal such as O-ring 17 is provided to effect a slideable watertight connection between the shaft and the casing. The piston is yieldably urged toward the initial safe position by a spring 18 of sutlicient strength to maintain the piston in the initial safe position after the arming wire has been removed until hydrostatic pressure against the head of the piston has increased to a predetermined value. The shaft 1'6 extends through a suitable aperture within plate 19 secured to the interior of the mine casing and is provided with a transverse bore 21 having an explosive train 22 disposed therein. As the piston is moved to the armed position, the explosive train is moved into alignment with a detonator Z3 and a second explosive train 24 thereby to establish an operative connection between the detonator and a booster charge 25.

There is secured to the shaft 16 a sleeve 26 having one end thereof preferably abutting plate 19 when the piston is in the initial unarmed position as shown on FIG. 1 thereby to limit further movement of the shaft 16 outwardly. A latch 27 preferably pivoted on plate 19 is yicldably urged against the sleeve 26 by spring 28. With latch 27 in the position shown on FIG. 1 switch 29 is closed and when the piston is moved to the armed position the latch is moved into engagement with shaft 16 by spring 23 and latches the piston in the armed position, causing switch 29 to be opened concurrently therewith.

There is also provided a water pump 31 preferably of the gear type having the inlet thereof in communication .with the outside of the mine casing by a duct 32 and a system of the mine. The outlet of the pump is connected by duct to a chamber 313 communicating with the head of piston 14. The valve 33 is maintained in an initial closed position by latch 3'7 engaging a complementary arm 32; moveable from an initial closed position in engagement with stop pin 39 to an open position in engagement with stop pin 41 by a resilient spring 42 when the latch is moved to the position shown on PEG. 2. Latch 37 is carried by shaft 43 having a shoulder 44 thereon urged by spring 45 from an initial position in which it is maintained by arming wire 13 passing through an aperture therein to the position shown on PEG. 2 when the arming wire is removed.

Pump 31 is connected to electric motor 46 for operation thereby as by the shaft 47 illustrated. There is also provided within the mine it) a starting switch 48 having an arm normahy locked by latch 49 in an initial open position and moveable by spring 51 to a closed position when the latch is actuated. Latch is carried by shaft 52 having a shoulder :33 thereon and urged by spring 54 from the position shown on FIG. 1 where it is retained by arming wire 13 passing through a hole therein to the position of FIG. 2 when the arming wire is removed. Movement of the shaft 52 to the moved position thereof unlatches switch 3 causing the switch to close its contacts and set the motor and pump into operation.

On FIG. 3 is shown the hydraulic system of the present invention according to another embodiment thereof, only suflicient of the arming system being shown on PKG. 3 to illustrate the operation of the hydraulic system. The hydraulic s stem of FIG. 3 is generally similar to that of FIGS. 1 and 2 in that the operation of pump 31 when supplied with water is necessary to move the piston 14 to an armed position. This diifers from the system of FIGS. 1 and 2, however, by the addition of a by-pass duct 55 interconnecting the duct 32 with the interior of cylinder 15' substantially as shown whereby the piston is not moved to the armed position except when the pressure within chamber as applied to the piston head exceeds the ambient water pressure by a predetermined amount.

The operation of the device will now be described. Let it now be assumed, by way of example, that the mine It has been released from an airplane in flight and the arming wire 13 attached to the airplane has been withdrawn from the mine. As the arming wire is withdrawn from shaft 52 latch 49 is disengaged from starting switch member 48 causing the switch to close. As the arming wire is withdrawn from shaft 43 the latch 37 is disen gaged from arm 38 causing the arm to be moved by'spring 42 to the position shown in FIG. 2 thereby opening the inlet duct to pump 31. The removal of arming wire from shaft 16 unlocks the arming piston 14 for movement to an armed position against the pressure of spring 18 when the pressure within chamber 36 has increased to a predetermined value.

The closure of switch 43 closes a circuit from battery 56 to motor 46 by way of normally closed switch 29 thereby setting the motor and pump into operation; As the mine enters the water the pump 31 is effective to pump water into chamber 36 until the pressure therein is increased sufficiently to move the piston 14 against the action of spring 18 to the armed position shown on'FIG. 2;

When this occurs the explosive train 22 is brought into alignment with detonator 23 and explosive train 24 thereby arming the mine. The piston is locked in this position by latch 27 which moves to a latching position in engagement with shaft 16 and opens switch 29 thereby interrupting the motor operating circuit and stopping the operation of the motor and pump. The device is now armed. i

eferring now to FIG. 3 on which is shown an alternative iorm of the hydrostatic system employed with the present invention, the operation of this embodiment of the invention is generally similar to that of FIGS. 1 and 2 with the exception that as valve 33 is opened, the interior of cylinder 15 is brought into communication with the ambient water by duct 55. Piston 44, therefore, now has hydrostatic pressure applied to both ends thereof and is not moved to an armed position until the pressure within chamber 36 exceeds that of the ambient water by a predetermined amount. This is of particular advantage when the device is launched from a considerable depth as from the torpedo tube of a submarine for the reason that movement of the piston to the armed position should be delayed for a period of time SllffiClCl'lt to prevent the arming of the device until it is at a safe distance from the submarine. In this embodiment an O-ring is preferably employed as shownat 57 to effect a water seal between the shaft i6 and plate 1 to prevent leakage of water therebetween.

Whereas the invention has been described with particularity with reference to a marine minelaunched from an aircraft, it is not so limited as it may be advantageously employed with a shallow water mine planted from a launching vessel or other launching device or even by hand, in which latter case the arming wire would, of course, be removed manually just prior to launching. The invention may be advantageously employed with various other types of underwater weapon preferably for use in shallow water, as desired. It may also be employed with moored mines of the type wherein the mine is moored at a shallow depth beneath the surface of the water.

Whereas the invention has been described with particularity with regard to two examples thereof which give satisfactory results, it is not so limited as various changes and modifications will be apparent to one skilled in the art, after understanding the invention, without departing from the spirit and scope of the invention and it is intended, therefore, in the appended claims, to cover all such changes and modifications.

What'is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An aircraft planted shallow water mine comprising, in combination,

a mine casing having a normally closed port therein, a water pump within said casing having the inlet thereof connectedto said port, means for opening said port as the mine is launched comprising a normally closed spring biased valve and an'arming wire secured to the aircraft and detachably connected to said valve for causing the valve to be kept closed until the arming wire is removed,

a closed water reservoir connected to the output of said a cylinder in communication with said reservoir and having a spring biased piston means slidably disposed therein and movable from an initial safe position to an armed position by water pressure applied thereto from said reservoir,

means for actuating said pump as the mine is launched comprising an electric motor, an electric power source within the mine, and means including a spring biased switch movable from a normally open position to a closed position as the mine is launched for establishing an electrical circuit from the motor to said power source.

2. A mine according to claim 1 including means for detachably connecting the switch to said arming wire in such manner that the switch is moved from an initial open position to the closed position as the arming wire is removed.

3. A mine according to claim 1 including means for detachably securing the piston means to the arming wire in such manner as to lock the piston means in the safe initial position until the arming wire is detached therefrom.

4. A mine according to claim 3 including a mine arming mechanism connected to said piston means and actuated thereby to an armed condition as the piston means moves to said armed position.

5. A shallow water mine arming mechanism comprisa spring biased arming piston movable within a cylinder disposed within the mine from an initial safe position to an armed position by water pressure applied thereto, and

a power driven water pump disposed within the mine and having the outlet thereof connected to said cylindcr and having the inlet thereof in communication with the ambient water within which the mine is planted for increasing the hydrostatic pressure of the water sufficiently to overcome the bias of said spring and move said piston to the armed position.

6. The arming mechanism according to claim 5 including means for setting the pump in operation as the mine is launched.

7. The arming mechanism of claim 6 including means for releasably retaining the piston in said initial safe position until the mine is launched.

8. The arming mechanism of claim 7 in which the means recited therein comprises a detachable arming wire, and

means for detaching the wire as the mine is launched.

9. An arming mechanism for a shallow water weapon comprising, in combination,

arming means within the weapon movable from an initial safe position to an armed position in response to hydrostatic pressure applied thereto in excess of -the pressure of the water at the depth at which the weapon is planted, and

a power driven water pump within the weapon having its outlet connected to said arming means and having its inlet in communication with the surrounding Water for increasing the pressure applied to the arming means sufiiciently to move the arming means to said armed position as the pump is actuated.

10. An arming mechanism according to claim 9 in which the arming means includes a piston moveable within a cylinder in response to hydrostatic pressure applied to the head thereof,

spring means for yieldably urging the piston toward said initial safe position,

and a duct for establishing a fluid connection between said cylinder and the surrounding water in a manner to additionally urge the piston toward the initial safe position by the pressure of the surrounding water whereby the piston is moved to said armed position only when the pressure applied thereto by said pump exceeds the pressure of the surrounding water by a predetermined amount.

References Cited by the Examiner UNITED STATES PATENTS 1,314,413 8/ 19 Martena 1027 1,513,107 10/24 Hammond 102-l3 3,095,815 7/63 Brockway et a1 1027 X SAMUEL FEINBERG, Primary Examiner. 

5. A SHALLOW WATER MINE ARMING MECHANISM COMPRISING, A SPRING BIASED ARMING PISTON MOVABLE WITHIN A CYLINDER DISPOSED WITHIN THE MINE FROM AN INITIAL SAFE POSITION TO AN ARMED POSITION BY WATER PRESSURE APPLIED THERETO, AND A POWER DRIVEN WATER PUMP DISPOSED WITHIN THE MINE AND HAVING THE OUTLET THEREOF CONNECTED TO SAID CYLINDER AND HAVING THE INLET THEREOF IN COMMUNICATION WITH THE AMBIENT WATER WITHIN WHICH THE MINE IS PLANTED FOR INCREASING THE HYDROSTATIC PRESSURE OF THE WATER SUFFICIENTLY TO OVERCOME THE BIAS OF SAID SPRING AND MOVE SAID PISTON TO THE ARMED POSITION. 